P-51D maneuvrability - what it was in reality ...

[GregP]

Go fly an AT-6 in a sim and then go fly a real one at 100 mph. Take the sims stick, put it into a 30° bank and pull on the stick with some force. Then, do it in a real T-6.

The sim T-6 absolutely doesn't do what the real T-6 does. I know that from personal inverted experience in a T-6. Felt like a snap-roll! Yes, the sim flies nicely at 150 mph and normal flight regimes, but the real T-6 will depart on you easily if you pull too hard and doesn't exactly recover quickly, either. They tailor sims to make the gaming experience a good one. Perhaps that's what Bill Marshall means ... the sim doesn't replicate the airplane very well near the edges of the envelope.

I used to take any of the fighters in Microsoft Flight Simulator, take off, roll it over and fly down the roads inverted at maybe 50 feet altitude. The real fighter won't do that, either ... unless you pump the primer handle to get fuel to the carb. But, that doesn't help the lack of oil because the real Merin or Allison doesn't have an inverted oil system. Again, the sim fails to be accurate.

I have flown a "real" sim. A friend of mine worked for Honeywell in Phoenix, AZ and had a simulator at home that required 5 big screens and 8 PC's. One PC for each screen and the other three were: Two for calculations and one as a server/calculator for the rest. I flew the Boeing 727 and 707 sims on it. They flew quite well and he could legally log time in it. It flew NOTHING like a gaming sim. It didn't kill you automatically, but it also wasn't exactly "forgiving" like gaming sims are. You needed to fly the numbers to get it to fly well. One time out of about 40, I managed to roll it on takeoff without killing myself.

Gaming sims? I can roll them all at 2 wingspan height and do just fine almost every time. Real airliners aren't quite so easy near the lower edge of the flight envelope.

I'm not talking about their data sets, I'm talking about the way they fly near the edge of the maneuvering envelope, both upper edges AND lower edges. The gaming sims generally do fine in the middle of the envelope, even if they DON'T exactly replicate the real-life handling characteristics. In most the gaming sims I have flown, the P-51 somehow just doesn't fly very well versus most of the other fighters for some reason ( at least, I haven't found one that does). In real life, it DOES fly well.

 

[Snautzer01]

Doesn't that render your point moot? Say the programmers had all the relevant data. If the computers cannot process that data due to lacking processing power, doesn't that still mean that sims cannot replicate flight characteristics?

Either way, that sim will not be accurate, right?

The point is what data is available to a party. What they can or will do with it. It is in my opinion wrong to state they have no acces or have no knowledge to data that o.p. said.
I have done archive research for a party and i can tell you more data, graphs etc is collected then one might think.

The difference real life vs a pc is a very dead horse. And not what the discussion between me and o.p. is about. That is about availability.

 

[GrauGeist]

Go fly an AT-6 in a sim and then go fly a real one at 100 mph. Take the sims stick, put it into a 30° bank and pull on the stick with some force. Then, do it in a real T-6.

The sim T-6 absolutely doesn't do what the real T-6 does. I know that from personal inverted experience in a T-6. Felt like a snap-roll! Yes, the sim flies nicely at 150 mph and normal flight regimes, but the real T-6 will depart on you easily if you pull too hard and doesn't exactly recover quickly, either. They tailor sims to make the gaming experience a good one. Perhaps that's what Bill Marshall means ... the sim doesn't replicate the airplane very well near the edges of the envelope.

I used to take any of the fighters in Microsoft Flight Simulator, take off, roll it over and fly down the roads inverted at maybe 50 feet altitude. The real fighter won't do that, either ... unless you pump the primer handle to get fuel to the carb. But, that doesn't help the lack of oil because the real Merin or Allison doesn't have an inverted oil system. Again, the sim fails to be accurate.

I have flown a "real" sim. A friend of mine worked for Honeywell in Phoenix, AZ and had a simulator at home that required 5 big screens and 8 PC's. One PC for each screen and the other three were: Two for calculations and one as a server/calculator for the rest. I flew the Boeing 727 and 707 sims on it. They flew quite well and he could legally log time in it. It flew NOTHING like a gaming sim. It didn't kill you automatically, but it also wasn't exactly "forgiving" like gaming sims are. You needed to fly the numbers to get it to fly well. One time out of about 40, I managed to roll it on takeoff without killing myself.

Gaming sims? I can roll them all at 2 wingspan height and do just fine almost every time. Real airliners aren't quite so easy near the lower edge of the flight envelope.

I'm not talking about their data sets, I'm talking about the way they fly near the edge of the maneuvering envelope, both upper edges AND lower edges. The gaming sims generally do fine in the middle of the envelope, even if they DON'T exactly replicate the real-life handling characteristics. In most the gaming sims I have flown, the P-51 somehow just doesn't fly very well versus most of the other fighters for some reason ( at least, I haven't found one that does). In real life, it DOES fly well.

There's also programming bias - in IL-2: Sturmovik, an I-16 can out climb and overtake an Fw190A-8 at 12,000 AGL.

Uh huh, right.

Or a Yak-9 can out dive an Me262A1-a with it's Jumo004's throttle to the firewall.

Sure, why not.

Off the shelf "combat sims" are games. They are for-profit entertainment only.

 

[drgondog]

So you do not know what they know or have in i.g. a knowledge bank. You think they etc
I get your point i do, but having been involved it can be very suprizing i can tell you that.
And yes there were, at least for what i was involved in, many trips to archives.
By far not all data was used. Pc are not powerfull enough then and still are not.

Never the less saying:


Is selling short. So i think you do not know what goes on there and/or what data has been achived. i have been to archives like quite a few others to support a certain game.) It is not always rehassing old and tired data,

Snautzer- I absolutely agree that I do not know 'what they know' but I DO know what it takes to combine aerodynamics with flight mechanics and generate a 'near accurate' simulation. I didn't even dive into stability and control or modeling asymmetric flight conditions .

What I am saying is that having close contact with some of the principals (Horkey) who designed the Mustang, I had access to a lot of data and reports that do not even exist - to my knowledge - in the hands of more than a handful. Some portals (AeroLibrary) have such because I gave it to them. That said, ven my repository is incomplete.

I Do presume with some degree of confidence - that there are no gamers with just what I have in my posession relevant to this discussion - on just the Mustang - unless they pulled off AeroLibrary fo example, or got from Lednicer.

Republic destroyed everything, as well as Rockwell when they bought NAA. Gruenhagen and Wagner were the last two that I am aware of, other than my co-author Lowell Ford - with full access to the record, reports, microfiche and microfilm that they wanted to look at- and they are Not technically inclined or had any reason to keep Performance Analysis, Stability and Control Reports that existed hither and yon as well as in the off-site microfilm depository at Stone Mountain. I have no idea what remains, where and to what level of basic detail remain anywhere for Grumman, Republic, Lockheed,etc. Do you?

The NARA archives have been pirated to death by uncrupulous researchers, particularly in the Wright Field Sarah Clark collection. But so much of the technical reports and specifications are no longer there - or hidden in obscure locations.

So, since you mentioned your own research at NARA - what did you find comparable to what I just showed you above for say, F6F, P-38, P-47, P-39, P-40, Spitfire, Hurricane, Yak 3, FW 190, Bf 109, etc?

Did you find Any 'old data' such as compete drag polars, CDP base values for fuselage, empennage, wing, etc - for ANY One single aircraft which was used in any game you are familiar with? Flight tests still exist but those are hopeless sources for technical data other than such relevant to the specific a/c flown and recorded. If you have enough test data, you can probably build a Total Drag table as f (altitude and airspeed) but even that is imprecise to say the least, as compressibility effects without wind tunnel tables are pure guesswork.

NACA/NASA is still a good source for technical papers - but not at the detail I presented above.

To summarize - I do not know 'what they know' with respect to a.) technical base data and charts, b.) understanding aerodynamics AND flight mechanics, c.) ability to perform analysis to predict and codify behavior of the physics of the wing/body based on both the fluid in which it is immersed and the control inputs to 'disturb' the wing/body.

God forbid diving into CFD because accurate lines for fuselage and wing/empennage are also mandatory - and mostly impossible to find.

Maybe my brain is incapable of crafting an approach that the very most competent Gamers use to overcome the issues I present? I can buy into that outcome, given a viable approach.

 

[tonycat77]

Snautzer- I absolutely agree that I do not know 'what they know' but I DO know what it takes to combine aerodynamics with flight mechanics and generate a 'near accurate' simulation. I didn't even dive into stability and control or modeling asymmetric flight conditions .

What I am saying is that having close contact with some of the principals (Horkey) who designed the Mustang, I had access to a lot of data and reports that do not even exist - to my knowledge - in the hands of more than a handful. Some portals (AeroLibrary) have such because I gave it to them. That said, ven my repository is incomplete.

I Do presume with some degree of confidence - that there are no gamers with just what I have in my posession relevant to this discussion - on just the Mustang - unless they pulled off AeroLibrary fo example, or got from Lednicer.

Republic destroyed everything, as well as Rockwell when they bought NAA. Gruenhagen and Wagner were the last two that I am aware of, other than my co-author Lowell Ford - with full access to the record, reports, microfiche and microfilm that they wanted to look at- and they are Not technically inclined or had any reason to keep Performance Analysis, Stability and Control Reports that existed hither and yon as well as in the off-site microfilm depository at Stone Mountain. I have no idea what remains, where and to what level of basic detail remain anywhere for Grumman, Republic, Lockheed,etc. Do you?

The NARA archives have been pirated to death by uncrupulous researchers, particularly in the Wright Field Sarah Clark collection. But so much of the technical reports and specifications are no longer there - or hidden in obscure locations.

So, since you mentioned your own research at NARA - what did you find comparable to what I just showed you above for say, F6F, P-38, P-47, P-39, P-40, Spitfire, Hurricane, Yak 3, FW 190, Bf 109, etc?

Did you find Any 'old data' such as compete drag polars, CDP base values for fuselage, empennage, wing, etc - for ANY One single aircraft which was used in any game you are familiar with? Flight tests still exist but those are hopeless sources for technical data other than such relevant to the specific a/c flown and recorded. If you have enough test data, you can probably build a Total Drag table as f (altitude and airspeed) but even that is imprecise to say the least, as compressibility effects without wind tunnel tables are pure guesswork.

NACA/NASA is still a good source for technical papers - but not at the detail I presented above.

To summarize - I do not know 'what they know' with respect to a.) technical base data and charts, b.) understanding aerodynamics AND flight mechanics, c.) ability to perform analysis to predict and codify behavior of the physics of the wing/body based on both the fluid in which it is immersed and the control inputs to 'disturb' the wing/body.

God forbid diving into CFD because accurate lines for fuselage and wing/empennage are also mandatory - and mostly impossible to find.

Maybe my brain is incapable of crafting an approach that the very most competent Gamers use to overcome the issues I present? I can buy into that outcome, given a viable approach.

Honest, have you thought about giving that data to some developers? They would pay big cash for it.
Get some NACA files on 1946 captured aircraft and you'd be sitting in liquid gold.

 

[Snautzer01]

Get some NACA files on 1946 captured aircraft and you'd be sitting in liquid gold.

Game developers have (and not only them i think people here have them too) have alot of them.

 

[Thumpalumpacus]

The point is what data is available to a party. What they can or will do with it. It is in my opinion wrong to state they have no acces or have no knowledge to data that o.p. said.
I have done archive research for a party and i can tell you more data, graphs etc is collected then one might think.

The difference real life vs a pc is a very dead horse. And not what the discussion between me and o.p. is about. That is about availability.

Right, then -- even if you're right, it's irrelevant.

 

[Snautzer01]

Right, then -- even if you're right, it's irrelevant.

I am right. Your opinion on what is relevant in this doent really matter nor has weight. As far as i know you are not a researcher nor have been active in flight sim communities. I have been.

 

[Thumpalumpacus]

I am right. Your opinion on what is relevant in this doent really matter nor has weight. As far as i know you are not a researcher nor have been active in flight sim communities. I have been.

I'm going by your point about the limit being the processing power of a pc. I don't care if you were the king of Germany -- if the computers cannot process the data, then the possession or lack of data doesn't matter.

This is simple logic, m'friend ... a field I am rather adept in if I do so allow.

 

[Greyman]

Anyone know of any interest (or efforts underway) to 3D scan existing airframes and running them through top-level / commercial 'wind tunnels' or simulators?

 

[GrauGeist]

Jerry Beckwith had some of the most accurate tools for flight modeling - his programs were based on NACA data.

 

[pbehn]

I know I know, sims aren't reality, but at least they have some aerodynamic modelling.
With that said, I don't really like to fly the P-51, it's usually starts with drop tanks and flying slow and above the b-17s or b-29s you're supposed to be escorting.

If you try to pull hard on it, the wing usually stalls suddenly before you know it.

I usually try to make head on passes after accelerating, once you're up to speed, no one except maybe the ta-152 can get to you.

Against it I try to go down on the ground, get them to overshoot me and usually they start to overheat and slow down since they don't get methanol injections like the late war axis planes, the AI also tries to follow you in scissors and it's always a bad idea.

My favorite American plane to fly is the p-47, it's unbeatable in a dive and boom and zoom, and its unbelievable fast down low even with bombs, it's a lot of fun, especially when you water inject it.

Here you illustrate the sim makers dilemma perfectly. You dont like the _P-51 sim. With loaded drop tanks the P-51 was marginal and prone to do a snap roll, extreme caution was advised to pilots, that is realistic. The P-47 was not a stellar performer low down and especially with bombs attached. Until it got dive brakes it could be very dangerous in a dive, but you like the sim representation.

 

[SaparotRob]

Playability versus accuracy.

 

[SuperAereo]

One thing that it does not often get mentioned is that German fighters (and their engines) in the last two years of the war were built in scattered facilities and largely by slave labour: in those circumstances their performance often was not as good as it should have been according to factory specs, due to inferior manufacture and less reliable systems...

 

[drgondog]

And you know that because of....??

Sorry drgondog but this is a bit thin. I am aware of your fast knowledge but i think game development is not were you excell.

There is more information gathered then a simple game can produce as a result. Clients hardware etc as a bottomline

It would be wrong i feel just by bulldozing it all on one heap of dung.
In fact i know that some developers have data some bookwriters will fight for.

Can you be more specific? What data that some book writers will fight for? What would a 'top sim team look like, education and work experience wise? Aside from a reasonable dive into airfoil section data, and the ability to develop a lift profile based on angle of attack, where are they drawing from to craft drag data, and what approximatios for curvilinear/asymmetric flight conditions?How do they deal with CG location changes for such a/c as P-51D as it burns internal fuel? How does the gamer construct the lower velocity gradient in 1G dive hich retards development of the Mcrit shock wave? How do they feed back the stick forces and requirement for left rudder input to keep the yaw in contrlol?

For example, flying a 51 in straight line cruise at constant altitude, RPM, MP in a straight line will require pitch trim over time as angle of attack reduces to maintain stable equilibrium CL? Does your optimal gamer make you experience very light stick forces in high G turn with aft cg?

Does the exhaust gas thrust for same MP steadily reduce at same MP as altitude decreases? How is that reflected in Vmax. Does Cooling drag kick its ass in climb? And what values does the gamer draw on re: Momentum recovery eflected as "delta HP Required".

 

[pbehn]

Playability versus accuracy.

In the sim world I can hop in a P-51 and maybe become an ace, in the real world I would probably prang it trying to taxi and certainly crash it trying to take off or land, if you could drop me at the controls at 25,000 ft over Germany flying straight and level would be a challenge, actually flying back home safely would be a chance in a thousand. Back in the day, low hours RAF and LW pilots had difficulty maintaining formation let alone surviving combat. Even looking at a record lap by a M/cycle on a Youtube video is nothing like the real thing, because your knee isnt scraping the tarmac at 140MPH and your body isnt full of adrenaline, it all seems very tame and easy.

 

[GrauGeist]

I had the advantage of both having a deep knowledge of WWII aircraft (Allied and Axis) as well as actually having logged many hours with my pilot's license, so I proved to be a dangerous adversary in sims. But they are absolutely nothing close to real life flight.

Ages ago, in the Jane's WWII Fighters multiplayer combat server, there was a well known Allied pilot, nicknamed "Monroe", who was a fantastic adversary with his P-47.
He commented many times that he wished that his actual P-47 performed half as well as his simulator's P-47 in game - he was a USAAF P-47 pilot in the ETO.

 

[Glider]

In the sim world I can hop in a P-51 and maybe become an ace, in the real world I would probably prang it trying to taxi and certainly crash it trying to take off or land, if you could drop me at the controls at 25,000 ft over Germany flying straight and level would be a challenge, actually flying back home safely would be a chance in a thousand. Back in the day, low hours RAF and LW pilots had difficulty maintaining formation let alone surviving combat. Even looking at a record lap by a M/cycle on a Youtube video is nothing like the real thing, because your knee isnt scraping the tarmac at 140MPH and your body isnt full of adrenaline, it all seems very tame and easy.

I cannot remember which British actor it was, but I remember one who pointed out that during flight training, he had two accidents when there was a mechanical failure, one where he had made a mistake and another when a second student had taxied into his aircraft on the ground. When he was posted to a front line squadron someone asked what he thought about being shot down and he replied as long as he survived he wouldn't mind as he could call himself a German ace. Apparently this didn't go down well.

 

[Clean32]

Hi

I've been reflecting on this aspect of P-51 Mustang characteristics and I couldn't get to any reasonable conclusion. I've heard that laminar wing reduced drag, but it will also stall earlier. However, I also read that P51 could turn very sharply and was quite controlable at high speeds.

So guys I would be grateful If someone could enlighten me on P51 maneuvrability (turning, rate of roll, handling at high speeds) in comparison to German Fighters like Fw 190 A or Bf 109G-K.

Regards,

Good luck, while there is a lot out there none of it is definitive and all requires interpretation as well as all being incomplete. so it very hard to get a good picture.
for example the P51 Near Laminar flow wing as it was not actually a Lamour flow was quite Fat and dragy. but it had a bucket load of advantages, it was fat enough to carry .50. it was actually 3 profiles, the inner wing being having quite a sweep. like a modern jet. the middle section being near laminar gave its controllable dive speed and its more conventional wing tips improved its low speed and tip stall characteristics. add to that it was bloody strong.
It was for its day a tech marvel and you can see its further development in the crescent wing of the valiant

but back to your comment " reduced drag" the inner section being at such an angle did reduce drag. but the overall wing design was not less dragy that say a spitfire.

so when we do comparisons in wings. the near identical profile of the top and bottom of the wing meant that when the shock wave formed it would form at the same place top and bottom at the same time.
where for example a P47 had the shock wave form much slower but only on the top of the wing. forcing the aircraft nose down.
and another and very important fact is the tail of the P51 is very thin

the spitfire wing being so much thinner formed a shock wave at faster speeds, but being thinner the tops and lower shock waves were not that far apart to the point where the tail could not overcome the effect.
But that's only one aspect and in not answering your question.

there are a myriad of really documented issues that can interfere or explain why this report is different to that report etc. for example, rearming the p51 required the amours to drag the ammo boxes over the wings, denting and scratching the wing skin. this had a large detrimental effect on the effectiveness of the wing. it was fixed by a ammo cartridge system.
but that added weight.
it reminds me of the spitfire and the universal wing. i think Parks wrote" it slower in the climb its heavier and we just don't want it" but manufacturing concerned got there way and the RAF got the universal wing, although not in its original form.
So if your looking for a definitive source of actual data on the P51 or any aircraft for that matter, well it just will not exist

 

[drgondog]

Good luck, while there is a lot out there none of it is definitive and all requires interpretation as well as all being incomplete. so it very hard to get a good picture.
for example the P51 Near Laminar flow wing as it was not actually a Lamour flow was quite Fat and dragy. but it had a bucket load of advantages, it was fat enough to carry .50. it was actually 3 profiles, the inner wing being having quite a sweep. like a modern jet. the middle section being near laminar gave its controllable dive speed and its more conventional wing tips improved its low speed and tip stall characteristics. add to that it was bloody strong.
It was for its day a tech marvel and you can see its further development in the crescent wing of the valiant

but back to your comment " reduced drag" the inner section being at such an angle did reduce drag. but the overall wing design was not less dragy that say a spitfire.

so when we do comparisons in wings. the near identical profile of the top and bottom of the wing meant that when the shock wave formed it would form at the same place top and bottom at the same time.
where for example a P47 had the shock wave form much slower but only on the top of the wing. forcing the aircraft nose down.
and another and very important fact is the tail of the P51 is very thin

the spitfire wing being so much thinner formed a shock wave at faster speeds, but being thinner the tops and lower shock waves were not that far apart to the point where the tail could not overcome the effect.
But that's only one aspect and in not answering your question.

there are a myriad of really documented issues that can interfere or explain why this report is different to that report etc. for example, rearming the p51 required the amours to drag the ammo boxes over the wings, denting and scratching the wing skin. this had a large detrimental effect on the effectiveness of the wing. it was fixed by a ammo cartridge system.
but that added weight.
it reminds me of the spitfire and the universal wing. i think Parks wrote" it slower in the climb its heavier and we just don't want it" but manufacturing concerned got there way and the RAF got the universal wing, although not in its original form.
So if your looking for a definitive source of actual data on the P51 or any aircraft for that matter, well it just will not exist

in a word 'Balderdash'